int sys(char s[])
{
    int i;
    for(i=0;;i++)
        if(s[i]==0)
            break;
    int j,k;
    for(j=0,k=i-1;j<i/2;j++,k--)
        if(s[j]!=s[k])
         return 0;
    return 1;

}

int main()
{
    printf("%d\n",1==sys("a"));
    printf("%d\n",0==sys("1234312"));
    printf("%d\n",1==sys("aba"));
    printf("%d\n",1==sys(""));
}
